Showing papers by "University of Paris published in 1983"
01 Mar 1983
TL;DR: In this article, it was shown that if f n is a sequence of uniformly L p-bounded functions on a measure space, and f n → f pointwise a, then lim for all 0 < p < ∞.
Abstract: We show that if f n is a sequence of uniformly L p-bounded functions on a measure space, and if f n → f pointwise a.e., then lim for all 0 < p < ∞. This result is also generalized in Theorem 2 to some functional other than the L p norm, namely → 0 for suitable j: C → C and a suitable sequence f n. A brief discussion is given of the usefulness of this result in variational problems.
2,080 citations
Book•
12 Dec 1983TL;DR: The techniques of the calculus of variation and of optimization proved to be successful for several optimal shape design problems however these remain expensive both in the qualification of the engineers required to understand the method and in computing time.
Abstract: The techniques of the calculus of variation and of optimization proved to be successful for several optimal shape design problems however these remain expensive both in the qualification of the engineers required to understand the method and in computing time. However it seems difficult to do without such techniques for 3-dimensional optimization problems. The field is well studied from the mathematical point of view but still in its beginnings from the industrial implementation side.
1,002 citations
TL;DR: In this article, the authors investigated the large time behavior of the solutions of MHD equations for a viscous incompressible resistive fluid and established the regularity properties and bounds on the solutions to the equations which are valid for all time.
Abstract: Some questions relating to the large time behavior of the solutions of MHD equations for a viscous incompressible resistive fluid are investigated. The physical system is briefly described and the functional setting of the equations, a flow in a bounded domain or in whole space with a space periodicity property in all directions. The main existence and uniqueness results for weak and strong solutions of the MHD equations are recalled. Regularity properties and bounds on the solutions to the equations which are valid for all time are established and the concept of functional invariant sets is introduced which is contained in the space of smooth functions if the data are sufficiently regular. The squeezing property of the trajectories are stated and it is shown that any functional invariant set for the MHD equations, and in particular any attractor, has a finite Haussdorf dimension. The flow is found to be totally determined for large dimensions by a finite number of parameters. 26 references.
914 citations
TL;DR: In this article, the diffusion effects induced by partial blocking of an electrode surface toward electron transfer are analyzed in the case where the blocking film is sprinkled with a large number of microscopic, active sites.
733 citations
TL;DR: In this article, the results of a search for single isolated electrons of high transverse momentum at the CERN p p collider were reported and the configuration of the events and their number were consistent with the expectations from the process p + p → W ± + anything, with W→e+ν, where W± is the charged Intermediate Vector Boso postulated by the unified electroweak theory.
630 citations
TL;DR: The mobility of rare-earth elements (REE) and U during hydrothermal alteration of the basalts at spreading centres has long been a matter of concern because of its bearing on the evolution and recycling of the oceanic crust.
Abstract: The mobility of rare-earth elements (REE) and U during hydrothermal alteration of the basalts at spreading centres has long been a matter of concern because of its bearing on the evolution and recycling of the oceanic crust1–6. Previous approaches to this problem have been indirect, through studies on altered dredged basalts or ophiolites. We report here sampling of hydrothermal vent waters from the East Pacific Rise (EPR) at 13° N7,8, which provides the first direct evidence of REE-enriched solutions which, however, leave the budget of these elements in the crust and the ocean rather unmodified. In contrast, uranium, like magnesium, is quantitatively taken up from the seawater during the hydrothermal process.
492 citations
TL;DR: Primary hairy root tissues as well as aseptic hairy root culture lines contain specific compounds that have been biologically characterized as opines, which have been synthesized and their electrophoretic behavior has been studied.
Abstract: Primary hairy root tissues as well as aseptic hairy root culture lines contain specific compounds that have been biologically characterized as opines These substances are agropine, mannopine, mannopinic acid, and agropinic acid; they have been synthesized and their electrophoretic behavior has been studied Hairy root tissues also contain agrocinopines According to the opine content of hairy root tissues, two types of Agrobacterium rhizogenes strains have been identified Agropine-type strains (A4, 15834, HRI) elicit roots containing agropine, mannopine, mannopinic acid, and agropinic acid, whereas mannopine-type strains (8196, TR7, TR101) elicit roots containing only mannopine, mannopinic acid and agropinic acid A rhizogenes strains catabolize the opines whose synthesis they induce in the hairy root tissues However, strain HRI only catabolizes agropine Except for strain HRI, all A rhizogenes strains studied contain three plasmids, of which the largest appears to be a cointegrate of the two others Transconjugants of A rhizogenes plasmids in A tumefaciens have been obtained by selection on opines Their properties have been studied and related to their plasmid content In the mannopine strain C58C1(pRi8196), the virulence functions and the opine-related functions are located on the same plasmid (pRi8196) In agropine strains the catabolic functions are dissociated: agropine degradation is specified by the virulence plasmid, which also specifies opine synthesis in hairy root tissue, however, mannopine, mannopinic acid and agropinic acid degradation are specified by the smaller plasmid Strain HRI contains only the virulence plasmid, which explains its inability to degrade mannopine, mannopinic acid, and agropinic acid
492 citations
Journal Article•
TL;DR: An attempt is made to resolve some divergences that have occurred in this context by the consideration of a unified model, with some practical applications.
Abstract: Various methods have been proposed for statistical inference of major genes by segregation analysis of human familial data. An attempt is made to resolve some divergences that have occurred in this context by the consideration of a unified model, with some practical applications.
430 citations
TL;DR: In this article, the authors consider general optimal stochastic control problems and the associated Hamilton-Jacobi-Bellman equations and develop a general notion of week solutions called viscosity solutions.
Abstract: We consider general optimal stochastic control problems and the associated Hamilton–Jacobi–Bellman equations. We develop a general notion of week solutions – called viscosity solutions – of the ami...
424 citations
TL;DR: In this paper, the authors examine, even at the risk of magnifying them somewhat for clarity, the potential dangers that some recent developments usually studied from other angles bring in their wake for the future of international law as a normative system intended to perform certain functions.
Abstract: 1. The purpose of this article is to examine, even at the risk of magnifying them somewhat for clarity, the potential dangers that some recent developments usually studied from other angles—the jus cogens theory, the distinction between international crimes and international delicts, the concept of a rule of general international law, the notion of obligation erga omnes—bring in their wake for the future of international law as a normative system intended to perform certain functions.
421 citations
TL;DR: In this paper, a search for electron pairs produced in p p collisions at s = 550 GeV was carried out, and it was reported that eight events which were interpreted as resulting from the process p +p→Z 0 + anything, followed by the decay Z0→e++e− or Z 0→e−e−+γ, where Z0 is the neutral Intermediate Vector Boson postulated by the unified electroweak theory.
TL;DR: Group contribution methods for dense fluid (liquid) mixtures are critically reviewed in this paper, where emphasis is placed on common sense rather than on mathematical derivations, and the purpose of the review is to stimulate discussion.
TL;DR: In this article, a complete vibrational study of crystalline V2O5 was performed and all the normal modes of vibration have been described in terms of potential energy distribution and the cartesian displacements.
TL;DR: In this paper, the authors investigated the relation between the speed of estimation and the metric structure of the parameter space Θ, especially in the case when its metric dimension is infinite and gave a construction for some sort of universal estimates the risk of which is bounded by C 2 r q(n) in all cases where the preceding theory applies.
Abstract: We investigate the relations between the speed of estimation and the metric structure of the parameter space Θ, especially in the case when its metric dimension is infinite. Given some distance d on Θ (generally Hellinger distance in the case of n i.i.d. variables), we consider the minimax risk for n observations: \(R_n (q) = \mathop {\inf \sup }\limits_{T_{n } \theta \in \Theta } {\text{IE}}_\theta [d^q (\theta , T_n )],\), T n being any estimate of θ. We shall look for functions r such that for positive constants C 1(q) and C 2(q) C 1 r q(n)≦R n(q)≦C2 r q(n). r(n) is the speed of estimation and we shall show under fairly general conditions (including i.i.d. variables and regular cases of Markov chains and stationnary gaussian processes) that r(n) is determined, up to multiplicative constants, by the metric structure of Θ. We shall also give a construction for some sort of “universal” estimates the risk of which is bounded by C 2 r q(n) in all cases where the preceding theory applies.
17 Mar 1983
TL;DR: This work model the speckle according to the exact physical process of coherent image formation and accurately represents the higher order statistical properties of speckel that are important to the restoration procedure.
Abstract: Speckle is a granular noise that inherently exists in all types of coherent imaging systems. The presence of speckle in an image reduces the resolution of the image and the detectability of the target. Many speckle reduction algorithms assume speckle noise is multiplicative. We instead model the speckle according to the exact physical process of coherent image formation. Thus, the model includes signal-dependent effects and accurately represents the higher order statistical properties of speckle that are important to the restoration procedure. Various adaptive restoration filters for intensity speckle images are derived based on different speckle model assumptions and a nonstationary image model. These filters respond adaptively to the signal-dependent speckle noise and the nonstationary statistics of the original image.© (1983) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
TL;DR: A storage-ring free-electron laser oscillator has been operated above threshold at a visible wavelength in this article, where the oscillator was operated at a cost of $6500.
Abstract: A storage-ring free-electron laser oscillator has been operated above threshold at a visible wavelength $\ensuremath{\lambda}\ensuremath{\simeq}6500$ \AA{}.
TL;DR: In this article, a long seismic refraction profile was carried out between southern Israel and Cyprus and the seismic energy was generated by 33 sea shots each of 0.8 t explosives.
Abstract: Summary. A long seismic refraction profile was carried out between southern Israel and Cyprus. The seismic energy was generated by 33 sea shots each of 0.8 t explosives and was recorded by land stations in Israel and Cyprus and by ocean bottom seismographs deployed along the profile.
The results showed that the continental crust of southern Israel thins towards the Mediterranean underneath a northward thickening sedimentary cover. Cyprus is underlain by a 35 km thick continental crust thinning south-wards and extending to Mt Eratosthenes. Between Mt Eratosthenes and the Israel continental shelf the crystalline crust is composed of high velocity (6.5 km s-1)material and is about 8 km thick. It is covered by 12–14 km of sediments and may represent a fossil oceanic crust.
TL;DR: In this article, the authors apply the inversion technique described in Part I [1] to models in which the depleted (MORB) mantle is created by extraction of continental crust results in a stable and self-consistent set of model data, including estimates of uncertainties on all the parameters.
01 Jan 1983
TL;DR: Soient A une variete abelienne definie sur le corps des nombres complexes, T le sous-groupe de torsion de A and X un sousschema ferme integre de A as mentioned in this paper
Abstract: Soient A une variete abelienne definie sur le corps des nombres complexes, T le sous-groupe de torsion de A et X un sous-schema ferme integre de A.
TL;DR: In this article, an extensive work on vibration-rotation spectra in the fundamental 1Σ+ electronic state of CO is reported and the Dunham coefficients Y are also reported.
TL;DR: In this article, the existence of a dual pairing between admissible stress and displacement fields in the context of Hencky plasticity was proved and they applied this to show that an extremal displacement field exists whenever the safe load condition holds.
Abstract: We prove the existence of a dual pairing between admissible stress and displacement fields in the context of Hencky plasticity. We apply this to show (i) that an extremal displacement field exists whenever the safe load condition holds; and (ii) that any extremal stress and displacement fields are related by a "saddle point condition," expressing in weak form the constitutive hypothesis of Hencky plasticity.
TL;DR: In this paper, a finite-cell-scaling analysis of the spin-1 antiferromagnetic Heisenberg-Ising chain was performed and it was shown that the ground-state properties are completely different than in the spin -text-onehalf{} case.
Abstract: A finite-cell-scaling analysis of the spin-1 antiferromagnetic Heisenberg-Ising chain, shows that the ground-state properties are completely different than in the spin-\textonehalf{} case. Between the $\mathrm{XY}$ gapless phase and the doublet ground-state N\'eel phase, it appears, in an extended range of the anisotropy ($0\ensuremath{\lesssim}\ensuremath{\lambda}\ensuremath{\lesssim}1.18$) a characteristic Heisenberg-phase with a nonmagnetic singlet ground state, nonzero gap, and exponential decay of the correlation functions.
TL;DR: In this article, the authors show how to obtain a canonical representation of non-measured foliations with saddle singularities on a given hyperbolic surface by extending Thurston's work.
TL;DR: A systematic petrological and chemical study of the volcanic products of the Phlegraean fields has been accomplished based on the new stratigraphy described by Rosi et al..
TL;DR: In this paper, multislip and latent hardening tensile tests are performed on α-iron single crystals at room temperature, in order to check the assumption of crystallographic glide restricted to the {110} planes and the {112} asymmetric planes.
TL;DR: In this article, the authors developed a stochastic calculus of variations for strong Markov processes with jumps, which is the analogous of the Malliavin calculus for variations on diffusions.
Abstract: The purpose of this paper is to develop a stochastic calculus of variations for R
n
-valuedstrong Markov processes with jumps x
t
,which is the analogous of the Malliavin calculus of variations on diffusions An integration by parts formula is established on a non Gaussian infinite dimensional probability space, in order to prove regularity of the probability law on R
n
of x
t
,for fixed time t Diffusions with jumps are also considered The connection between the calculus of variations and the representations of martingales for jump process is exhibited
TL;DR: In this article, the authors measured the acquisition and decay of small-field viscous magnetization as a function of temperature (9-500°C) for four synthetic magnetite dispersions ranging in mean particle size from 0.04 to 0.22 p at room temperature.
Abstract: Summary
Acquisition and decay of small-field viscous magnetization have been measured as a function of temperature (9-500°C) for four synthetic magnetite dispersions ranging in mean particle size from 0.04 to 0.22 pand at room temperature only for an additional six samples (2-100 μm). Room-temperature viscous magnetization is pronounced in the single-domain range, slight between 0.1 and 5 μm, and again substantial in the intermediate multidomain range (10-15 μm). In all experiments, the acquisition rate exceeded the decay rate, resulting in residual undecayed viscous remanent magnetization (VRM) after a zero-field decay time equal to the time of exposure to a field. Viscous magnetization is enhanced at elevated temperatures but not in direct proportion to absolute temperature. Instead, there appears to be a low-temperature (< 20°C) threshold below which viscous effects are negligible and an approach to saturation at high temperature. VRM produced isothermally at a given temperature is significantly more difficult to erase by heating to a higher temperature than most thermal activation theories predict. Furthermore, even in quite brief experiments, the viscosity coefficient S= |σJ|σlog t| increased with time, the increase being more pronounced at high temperature. The implications of these observations are that viscous overprinting of natural remanent magnetization in magnetite-bearing rocks, particularly during burial or intrusive reheating, may be more extensive and more difficult to erase than previously believed.
TL;DR: The results obtained from these studies show that the depletion of the phospholipid membrane content could account for the altered functional activity of palmitoylcarnitine transferase I.
Abstract: Palmitate oxidation by liver mitochondria from rats treated with d-galactosamine (GalN) was markedly inhibited, 3 h after administration.
1
The mitochondrial defect responsible for this inhibition was shown to be an inhibition of the activity of palmitoylcarnitine transferase I (EC 2.3.1.21).
2
Apparent Km of the enzyme remained unchanged whereas apparent V was reduced by 30%.
3
Addition of 10 mM GalN did not impair the activity of palmitoylcarnitine transferase I in mitochondria isolated from normal rats.
4
Inhibition of palmitoylcarnitine biosynthesis by GalN treatment was completely reversed by phospholipid supply.
5
At this stage of intoxication, mitochondrial phospholipid content was decreased whereas incorporation of [14C]palmitate into phospholipids in isolated hepatocytes was drastically inhibited; the phosphatidyl-choline/phosphatidylethanolamine ratio was reduced by 33%.
The results obtained from these studies show that the depletion of the phospholipid membrane content could account for the altered functional activity of palmitoylcarnitine transferase I.